mpc85xx: Add support for SBC8548 (updated)

Add support for Wind River's SBC8548 reference board.

Signed-off by: Joe Hamman <joe.hamman@embeddedspecialties.com>
Signed-off by: Andy Fleming <afleming@freescale.com>
diff --git a/Makefile b/Makefile
index 47db5b7..d3608fd 100644
--- a/Makefile
+++ b/Makefile
@@ -2025,6 +2025,9 @@
 	fi
 	@$(MKCONFIG) -a SBC8540 ppc mpc85xx sbc8560
 
+sbc8548_config:		unconfig
+	@$(MKCONFIG) $(@:_config=) ppc mpc85xx sbc8548
+
 sbc8560_config \
 sbc8560_33_config \
 sbc8560_66_config:      unconfig